<template>
  <div class="progress-circle">
  	<svg :width="radius" :height="radius" viewBox="0 0 100 100" version="1.1" xmlns="http://www.w3.org/2000/svg">
  	  <circle class="progress-background" r="50" cx="50" cy="50" fill="transparent"/>
  	  <circle class="progress-bar" r="50" cx="50" cy="50" :stroke-dasharray="dashArray" :stroke-dashoffset="dashOffset"/>
  	  <!--stroke-dasharray表示描边，stroke-dashoffset描边的偏移-->
  	</svg>
  	<slot></slot>
  </div>
</template>

<script type="text/ecmascript-6">
export default {
  props: {
    // 从父组件传入的半径值
    radius: {
      type: Number,
      default: 100
    },
    // 从父组件传入的播放比例
    percent: {
      type: Number,
      default: 0
    }
  },
  data () {
    return {
      dashArray: Math.PI * 100 // 圆的周长
    }
  },
  computed: {
    dashOffset () {
      return (1 - this.percent) * this.dashArray // 播放进度的偏移计算
    }
  }
}
</script>

<style scoped="scoped" lang="stylus" rel="stylesheet/stylus">
  @import "~common/stylus/variable"

  .progress-circle
    position: relative
    circle
      stroke-width: 8px
      transform-origin: center
      &.progress-background
        transform: scale(0.9)
        stroke: $color-theme-d
      &.progress-bar
        transform: scale(0.9) rotate(-90deg)
        stroke: $color-theme
</style>
